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PHP2Shell in Zabbix: is it affected and how to fix it

How to check the PHP version Zabbix uses

Run the command for your setup. A version at or above 8.2.35, 8.3.36, 8.4.27 or 8.5.12 in its branch is fixed; older branches are fixed only by a vendor build that says so.

php -v
docker exec <zabbix-web> php -v

The command-line php can differ from the PHP that serves the site. To be sure, check the web SAPI (a temporary phpinfo() page behind authentication, or the panel's PHP settings) and remove it afterwards. Our version checker compares a version number for you.

🔎 Got a version number? Paste it into the PHP2Shell checker →

How to fix PHP2Shell in Zabbix

Debian/Ubuntu: sudo apt-get update && sudo apt-get install --only-upgrade 'php8.3*' (repeat for each installed PHP version).
RHEL/Alma/Rocky/Amazon Linux: sudo dnf upgrade 'php*'.
Restart PHP: sudo systemctl restart php8.3-fpm (or php-fpm), and fully restart Apache if it uses mod_php; a graceful reload is not enough.
Distributions often backport the fix without changing the PHP version, so compare the package version or changelog with the vendor's advisory.

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If you cannot patch yet

Set session.upload_progress.enabled = 0 where applications cannot override it (php.ini, php_admin_value in the FPM pool or Apache config), and restart PHP.
On PHP 8.5, set fatal_error_backtraces = 0.
PHP's interim advice also covers memory_limit and a low post_max_size; follow the remediation page exactly, because these settings only reduce some paths.
Restrict access (VPN, IP allowlist) or take the service offline if it runs PHP 8.1 or older with no vendor backport. WAF rules help but are not a fix.

FAQ

Is Zabbix affected by PHP2Shell?

Affected if the PHP underneath is older than the fixed releases. Zabbix frontend packages use the operating system's PHP, so update it. The official Zabbix web Docker images (Alpine PHP 8.5) had not been rebuilt since the fix at the last check. We found no Zabbix statement.

Does updating Zabbix itself fix CVE-2026-109618 and CVE-2026-109619?

Only if the update contains fixed PHP. PHP2Shell is a flaw in the PHP interpreter, so what matters is the PHP that Zabbix runs on. Check the version after updating.

Which PHP versions fix PHP2Shell?

PHP 8.2.35, 8.3.36, 8.4.27 and 8.5.12, released 21 October 2026. PHP 8.1 and older get no release from the PHP project; only vendor builds with a backport (or a self-built source patch for 7.4, 8.0 and 8.1) fix them.

What if Zabbix has no fix yet?

Keep its PHP-based web interface off the internet (VPN or IP allowlist), apply PHP's interim settings such as disabling session upload progress, and install the vendor update as soon as it ships. Interim settings reduce risk but are not a fix.

← All products that bundle PHP

Sources

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Unofficial summary of public sources. This site is not affiliated with the vendor or the PHP project and hosts no exploit code.